The present invention relates to glass slides.
As is well known, glass slides are used to receive specimens which may be examined under a microscope. Such slides have areas adjacent and coplanar with the specimen support areas which are matted so as to receive writing for identifying the slides.
These matted areas of the slides can be achieved either by acid etching, by sandblasting, or by grinding. Acid etching has the disadvantage of limiting the action only to the surface of the slide, so that as a result of such etching the slide is not rendered sufficiently opaque at the matted area to assure easy legibility of writing at the matted area. Sandblasting results in pits which are relatively deep, so that the matted area has an undesirable coarseness which prevents the writing from being legible because, for example, ink will be readily absorbed into the relatively deep pits.
A ground matted area is preferable because it is possible through grinding to achieve the desired opacity which will render writing easily legible while at the same time avoiding the degree of coarseness inherent in sandblasting, so that perfectly legible writing can be easily achieved through a matted ground area on a glass slide.
It is already known to provide glass slides with matted areas by way of grinding procedures, as shown, for example, in U.S. Pat. No. 3,636,663.
However, experience has shown that certain drawbacks are encountered in the use of slides which have matted ground areas. During the grinding operations small particles of glass which are cut from the slide by the grinding elements cling to the glass so that tiny particles of glass become undesirably attached to the slide so as to interfere not only with the writing on the matted area but also with the deposition of specimens and the examination thereof. Furthermore, during the grinding operations it is difficult to maintain the glass slides properly oriented with respect to the grinding elements, so that the ground areas are not always of the desired uniform width.